Python requirements: Allow newer meson versions
Python requirements: Allow newer meson versions

Meson fixed the incompatibility with Python 3.5.2 introduced in meson
0.53.0, and we can use newer versions again.

Upstream fix: https://github.com/mesonbuild/meson/pull/6498

Fixes #1288

Signed-off-by: Philipp Wagner <5a4b10454c30419e54a1570be358a516ff84bb63@lowrisc.org>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan